title: [Analysis of resistance tendency of bloodstream-infecting pathogens in China].
abstract: OBJECTIVE
  To investigate the resistance profiles and the trend of bloodstream-infecting pathogens isolated from hospitalized patients during 2004-2010.
  
  
  METHODS
  The bloodstream isolates were collected from 18 hospitals in 17 cities. Minimum inhibition concentrations (MIC) were determined using the agar dilution method recommended by CLSI (Clinical and Laboratory Standards Institute), and susceptibility results were analyzed according to the 2011 CLSI guideline.
  
  
  RESULTS
  Among the 2004-2005, 2007-2008 and 2009-2010 periods, the proportions of clinical isolates were similar; 43.1% (149 isolates), 34.0% (151 isolates) and 47.5% (776 isolates) for Gram positive strains, 56.9% (197 isolates), 66.0% (293 isolates) and 52.5% (858 isolates) for Gram negative strains, respectively. The isolating rate of MRSA was 54.1% (20/37) in 2007-2008, which was the highest among the 3 periods during 2004 to 2010, while it decreased in 2009-2010 (36.5%, 62/170). The MRCNS proportions were similar across the 3 periods. One (1.8%) vancomycin-resistant Enterococcus faecium and 1 linezolid-resistant Enterococcus faecalis were found. Although the isolating rates of penicillin non-sensitive strains (oral) were similar between 2009-2010 and 2007-2008 [54.5% (6/11) and 53.9% (7/13), respectively], the resistant rates increased from 0% in 2007-2008 to 30.8% (4/13) in 2009-2010. The results were similar according to the non-meningitis criterion (IV), and the susceptibility rates decreased from 100.0% (11 isolates) in 2007-2008 to 84.6% (11/13) in 2009-2010. ESBL-harboring strains in E. coli were similar among the 3 periods during 2004 to 2010 [66.7% (30/45), 73.2% (71/97) and 67.9% (233/343), respectively]. ESBL-producing strains in Klebsilla pnuemoniae decreased year after year, 72.4% (21/29), 50.0% (18/36) and 41.1% (65/158) in 2004-2005, 2007-2008 and 2009-2010, respectively. Except that the sensitive rate of Enterobacter cloacae to ertapenem was 80% (32/40), the sensitive rates of other strains to carbapenems were still above 90% and the resistance rates were less than 5%. Acinetobacter baumannii had the highest multi-drug resistance rate (81.8%, 81/99). One strain (1.0%, 1/99) of Acinetobacter baumannii isolated in 2009-2010 was reported to be pan-resistant.
  
  
  CONCLUSIONS
  We are facing a more serious situation of bacterial resistance. Acinetobacter baumannii resistance was most serious, usually with the characteristics of multiple drug resistance, and even pan-resistance. Carbapenems remain to be the most effective against enterobacteriaceae. Strains resistant to novel antibiotics (linezolid and tigecycline) have emerged.
authors.affiliation: Institute of Clinical Pharmacology, Peking University First Hospital, Beijing 100191, China (Email: lyzx5857@163.com).
authors.forename: Yuan
authors.initials: Y
authors.lastname: Lü
authors.forename: Yun
authors.initials: Y
authors.lastname: Li
authors.forename: Feng
authors.initials: F
authors.lastname: Xue
authors.forename: Xiu-zhen
authors.initials: XZ
authors.lastname: Zhang
authors.forename: Yun-jian
authors.initials: YJ
authors.lastname: Hu
authors.forename: Yu-fen
authors.initials: YF
authors.lastname: Jin
authors.forename: Yun-zhuo
authors.initials: YZ
authors.lastname: Chu
authors.forename: Zhi-dong
authors.initials: ZD
authors.lastname: Hu
authors.forename: Jian-hong
authors.initials: JH
authors.lastname: Zhao
authors.forename: Shi-yang
authors.initials: SY
authors.lastname: Pan
authors.forename: Wang-sheng
authors.initials: WS
authors.lastname: Zhao
authors.forename: Bi-jie
authors.initials: BJ
authors.lastname: Hu
authors.forename: Yun-song
authors.initials: YS
authors.lastname: Yu
authors.forename: Qiu-lian
authors.initials: QL
authors.lastname: Deng
authors.forename: Jian
authors.initials: J
authors.lastname: Yang
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Wen-en
authors.initials: WE
authors.lastname: Liu
authors.forename: Xiao-ju
authors.initials: XJ
authors.lastname: Lü
authors.forename: Ya-Jing
authors.initials: YJ
authors.lastname: Yang
authors.forename: Ling
authors.initials: L
authors.lastname: Zhou
authors.forename: Fang
authors.initials: F
authors.lastname: Dong
authors.forename: Wei-ling
authors.initials: WL
authors.lastname: Fu
authors.forename: Xiu-li
authors.initials: XL
authors.lastname: Xu
authors.forename: Feng-yan
authors.initials: FY
authors.lastname: Pei
authors.forename: Bin
authors.initials: B
authors.lastname: Yang
authors.forename: Ling
authors.initials: L
authors.lastname: Meng
authors.forename: Ping
authors.initials: P
authors.lastname: Ji
authors.forename: Shan
authors.initials: S
authors.lastname: Wang
mesh_terms: D040981:Acinetobacter baumannii / Q000187:drug effects / Q000302:isolation & purification; D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D016470:Bacteremia / Q000453:epidemiology / Q000382:microbiology*; D015780:Carbapenems / Q000494:pharmacology; D002648:Child; D002681:China / Q000453:epidemiology; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology; D024901:Drug Resistance, Multiple, Bacterial; D006090:Gram-Negative Bacteria / Q000187:drug effects* / Q000302:isolation & purification; D006094:Gram-Positive Bacteria / Q000187:drug effects* / Q000302:isolation & purification; D006801:Humans; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests
chemical_list: D000900:Anti-Bacterial Agents; D015780:Carbapenems